add Mark Shannon
diff --git a/Misc/ACKS b/Misc/ACKS
index af0cd5f..44194fd 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -774,6 +774,7 @@
 Denis Severson
 Ian Seyer
 Ha Shao
+Mark Shannon
 Richard Shapiro
 Bruce Sherwood
 Alexander Shigin